1. Field of the Invention
The present invention relates to a fuel injection apparatus without using a throttle opening sensor for an internal combustion engine to detect quickly an acceleration state of the engine and to effect fuel injection at the time of acceleration of the engine in non-synchronism with a crank angle or an ignition timing.
2. Discussion of Background
A conventional fuel injection apparatus for an internal combustion engine for an automobile is adapted to inject fuel in correspondence to an intake air quantity sucked into the combustion chamber of the engine. In the conventional fuel injection apparatus, there has been found a delay in fuel supply to the combustion chamber due to a delay of detecting the intake air quantity or a delay of transmitting the fuel in a time period from the injection into the intake air pipe to the suction into the combustion chamber in a transition state such as an acceleration of engine. Accordingly, it was difficult to maintain the optimum air-fuel ratio of the mixture.
In such state, it is necessary to increase an amount of fuel as soon as an acceleration state is detected. In the conventional fuel injection apparatus, a throttle opening sensor was used as an acceleration state detecting means in order to detect quickly a state of acceleration, and fuel was injected in non-synchronism with a crank angle or an ignition timing under the conditions that the accelerating state was detected and a change of the output of the throttle opening sensor exceeds a predetermined value, the detection being carried out at predetermined time intervals.
The conventional fuel injection apparatus had, however, such disadvantage that a throttle opening sensor was needed to detect the accelerating state and therefore, the manufacturing cost increased.